Rocking chairs

ABSTRACT

A mount for tiltably mounting the seat of a chair on a base, and a chair including such a mount, the mount comprising a plurality of pads of resilient material such as rubber trapped between an upright centre plate and a pair of angle brackets arranged with their upright webs parallel to the centre plate. The centre plate is attached to the base whilst the angle brackets are attached to the seat via a support plate or plates supported by, but not attached to the centre plate to take the major part of the weight of the seat.

United States Patent Tranter et al.

[451 July 30, 1974 ROCKING CHAIRS [75] Inventors: Arthur Tranter, West l-lagley; John Dillwyn Olson, Wightwick, both of 211 Appl. No.: 332,175

Related U.S. Application Data [63] Continuation-impart of Ser. No. 93,l22, Nov. 27,

I970, abandoned.

482,529 3/l938 Great Britain 297/303 6l6,243 1/1949 Great Britain 248/375 672,578 5/l952 Great Britain 248/373 Primary Examiner-Marion Parsons, Jr. Attorney, Agent, or Firm-Marvin Feldman; .l. B.

Felshin [57] ABSTRACT A mount for tiltably mounting the seat of a chair on a [52] U.S. Cl. 248/375, 297/303 base, and a hair including such a mount, the mount [51] Int. Cl. A47c 3/18 ompri ing a plurality f pads of resilient material [58] Field of Search 248/373, 374, 375; su h as ubber trapped between an upright centre 297/303 plate and a pair of angle brackets arranged with their upright webs parallel to the centre plate. The centre [56] References Cited plate is attached to the base whilst the angle brackets UNITED STATES PATENTS are attached to the seat via a support plate or plates supported by, but not attached to the centre plate to iiii'fifii 135i???) lfiitl'i aii:iiiiiiiiiiiiiiiiiiiiii: 533/333 take the tttttittt Part of ttttt weight of the teat- FORElGN PATENTS OR APPLICATIONS 5 Claims, 7 Drawing Figures 188,617 l/l957 Austria 248/375 21 2 O 21 i9 23 D 24 iii 22 11 17 is ROCKING CHAIRS CROSS-REFERENCES TO RELATED APPLICATIONS This application is a Continuation-in-Part of copending application Ser. No. 93,122 filed 27th Nov. 1970, and entitled Improvements in Rocking Chairs, and now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a mount for tiltably mounting the seat of a chair on a base and also relates to a chair including such a mount, whereby a person seated on the chair can urge the seat of the chair to undergo rocking movement relative to the base of the chair which stands on a floor surface.

2. Description of the Prior Art Various proposals have been made for rocking chairs in which one or more pads of resilient material such as rubber were interposed between a member fixed with respect to the seat of a chair anda further member fixed with respect to the base of the chair so that relative rocking movement can take place by distortion of the rubber or other resilient material.

In particular British Pat. Specifications Nos. 616,243 of Witney and 672,578 of Stoll disclose arrangements of this type.

However, such prior art chairs have had serious disadvantages, in particular with regard to the transfer of the weight of the seat and the occupant through the mounting to the base. In each of the Specifications referred to above, the weight is transferred through the resilient pad which is placed in shear or compression, thereby reducing the life of the mounting and giving rise to a sensation of insecurity to an occupant of the chair.

BRIEF SUMMARY OF THE INVENTION It is an object of the invention to provide an improved mount and a rocking chair incorporating such a mount which avoids these disadvantages.

According to the invention there is provided a mount for tiltably mounting the seat of a chair on a base, the mount comprising a rigid upright centre plate means, having a midportion supported by a portion of the base and having two free end portions disposed at opposed lateral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat;

a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof;

resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween;

and a support plate means interposed between the top webs and the seat and supported by said centre plate means to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base.

Support pivots may be mounted on respective free end portions of the centre plate means and a pair of support plates may be provided, each interposed between the top web and the seat at a respective lateral side thereof and each resting on a respective one of said support pivots to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base, the support plates and support pivots having co-operating contact surfaces which remain in contact throughout rocking movement of the seat relative to the base.

According to a further aspect, the invention comprises a rocking chair incorporating a mount as set out above in the preceding two paragraphs.

The base may comprise a floor engaging part and a spindle mounted for rotation relative to the floor engaging part, said spindle constituting said portion of the base on which the centre plate means is supported.

BRIEF DESCRIPTION OF THE DRAWINGS A mount for a rocking chair and a chair embodying the mount will now be described by way of example only with reference to the accompanying drawings, wherein:

FIG. 1 is a diagrammatical transverse sectional view of'a base and mount for a seat,

FIG. 2 is a diagrammatical perspective view of the mount shown in FIG. 1,

FIG. 3 is a general perspective view of a rocking chair of the type with which the invention is concerned,

FIG. 4 is an exploded perspective view of the base and mount of the rocking chair shown in FIG. 3.

FIG. 5 is a front elevational view of the mount and base,

FIG. 6 is a plan view of the mount and base,

FIG. 7 is a side elevational view of the mount and base DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 of the drawings are intended to illustrate diagrammatically the base and mount of a rocking chair incorporating resilient pads to enable rocking movement to take place between the base and the seat of the chair which is attached to the mount.

The remaining figures of drawings illustrate a rocking chair having a mount base of the same type and operating in exactly the same manner as that shown in FIGS. 1 and 2 but, in order to establish clearly the mode of operation of the mount with which the invention is particularly concerned, the diagrammatic representations of FIGS. 1 and 2 will be referred to firstly.

FIG. 1 illustrates abase 10, partly broken away for clarity and having mounted thereon a mount 11 to which a seat (not shown) of a rocking chair can be attached.

The base 10 includes a plurality of legs 12 which radiate outwardly on a sleeve 13 within which is provided a spindle 14. The spindle 14 is rotatably mounted and suitable bearing bushes 15, 16 are provided to assist in the mounting of the spindle.

The mount 11 is secured between the top of the spindle 14 and the underside of a seat of the chair which has been omitted from FIGS. 1 and 2 of the drawings for clarity. The mount basically comprises a bar of inverted T-shape in cross-section, the bar being indicated at 17. The upright 18 of the T extends upwardly away from the spindle 14 and its top end is in contact with the underside of a mounting plate 19 which is intended to be secured to the seat ln this way, the weight of the seat and of the occupant of the chair is transmitted largely through the upright web 18 via its line of contact which extends along the top of the upright web as indicated at 20.

A pad 21 of resilient material is interposed between each face of the upright web 18 and a respective downwardly depending flange 22 of an angle bracket 23. The angle bracket 23 is provided with openings (not shown) through which are passed bolt and nut assemblies 24 which clamp the two flanges 22, the resilient pads 21 and the upright flange 18 together. If desired, the bolt and nut assemblies could be omitted and replaced by other means of securing such as for example adhesive means or some form of bonding which would secure the resilient pads and the web and flanges together. If desired, the adhesive or bonding can be used in additon to the bolt and nut assemblies.

The horizontal top flanges 25 of the angle brackets 23 are provided with suitable fixing holes, for example as indicated at 26 in FIG. 2, whereby they can be secured to the underside of the support plate 19 to which the seat is attached. Preferably, there is some slight give in the attachment of these flanges 25 to the mounting plate 19, this being achieved by, for example making the holes 26 oversized with respect to the bolts used to secure the assembly together or even by making the holes 26 elongate in form. This degree of give is desirable to assist in the rocking movement of the seat relative to the base of the chair but does not make the occupant of the chair feel insecure because the weight of the seat and the occupant is very largely transmitted to the base via the upright web 18 of the bar. Thus, there is little weight transmission through the angle brackets 22 and the bolt and nut assemblies 24. The resilient pads 21 are not subjected to shearing forces but tend to undergo only extending and compressing forces as will now be described.

The rocking action of the seat relative to the base is due solely to the resilience of the pads 21, since the bar 17 and angle brackets 23 are rigid and do not undergo any significant flexing movement themselves.

The bar 17 is arranged transversely with respect to the seat so that it extends from side to side. As seen in the drawings, the angle brackets 23 are disposed generally parallel to the bar 17, as are the resilient pads 21. Thus, when the occupant of the chair desires to rock backwards and forwards he can readily do so and this rocking movement is achieved by alternate compression and relaxation of the rubber or other resilient material of the pads. It will be appreciated that, whilst one pad is under compression, the other pad will tend to be relaxed. If there is physical bonding or an adhesive connection between the surfaces of the pads and the associated upright web and flanges then it is possible for the pads to go into a condition of extension during the rocking movement and not merely a condition of relaxation.

The amount of deflection of the seat during rocking can be preset by means of the bolt and nut assemblies 24 which can be tightened or loosened as desired, thus compressing or relaxing the rubber pads overall. This is one of the reasons why the holes 26 in the horizontal flanges 25 of the angle brackets are made slightly oversize, so that the bolts which attach the horizontal flanges to the mounting plate 19 and the seat can be adjusted in accordance with the adjustment of the bolt and nut assemblies 24. It will be appreciated that, when the pads 21 are firmly compressed between the flanges 22 of the angle brackets, the rocking action will be stiffer than when the bolt and nut assemblies 24 are relatively slack and hence the resilient pads 21 are not compressed significantly in their at rest positions.

The spindle 14 is, as mentioned above, rotatably mounted within the base and it will be appreciated that the seat of the chair can therefore be rotated relative to the base. However the rocking motion will always take place in a fore and aft direction relative to the seat since the mount 11 also rotates with the seat.

Turning now to the remaining figures of the drawings, FIG. 3 illustrates a typical chair embodying a mount according to the invention. The chair 30 comprises a shell 31 which may be of wood or of a synthetic plastics material such as expanded polystyrene or polyurethane foam. The shell is covered with upholstery and may be provided with suitable cushions 32.

The shell 31 is mounted on a base generally indicated at 32 having five equiangularly spaced legs 33. A mount as shown in more detail in the remaining figures of the drawings, is interposed between the base and the shell 31.

FIG. 4 shows in exploded perspective, the components of the mount incorporated in the chair of FIG. 3. The mount is shown in assembled condition in FIGS. 5, 6 and 7 of the drawings.

The spindle 34 of the base is, in this case, slightly tapered so as to be narrower at the top than at the bottom and is inserted into a correspondingly tapered socket 35 defined between two rigid centre plates 36 each of which is formed as a pressing in a suitable metal such as steel and is provided with a strengthened edge portion 37. The edge portion 37 surrounds a hollow face portion 38. Each centre plate 36 has two such face portions 38 and these receive respective pads 39 of a resilient material such as rubber. The pads 39 are trapped between the associated plate 36 and a depending web 40, of an associated angle bracket. As can be seen from FIG. 4 of the drawings, two such angle brackets 41 and 42 are provided and each such angle bracket is made as a pressing in sheet steel. A central hollowed portion 43 is provided in each case so that the angle bracket does not foul the centre plate means 36 during rocking movement of the chair.

The angle brackets have downwardly depending webs 40 and also have top horizontal webs 44 which, in use, extend generally parallel to the underside of the seat of the chair. These horizontal webs 44 are provided with suitable attachment holes 45 through which bolts can be passed to secure the angle brackets to a pair of support plates 46 disposed at opposite lateral sides of the centre spindle 34.

The support plates are generally rectangular in plan view but have a generally part cylindrical concave seat formed on their undersides as indicated at 47 and this seat is adapted to rest on a support pivot 48 which has a mating generally part cylindrical top and which is formed of a low friction material such as nylon or another suitable synthetic plastics material.

Two such support pivots 48 are provided one being disposed at each of the opposed lateral sides of the mount in shoulders 49 provided at the upper edges of the centre plates 36. The centre plates are so formed that a hole is defined at 50 in the centre of the shoulder 49 and this receives a locating pin 51 formed integrally with the underside of the associated support pivot.

The support plates 46 are provided with bolt holes 52 through which bolts 53 can be passed, these bolts then linking the support plates 46 to the angle bracket 41, since the bolts 53 also pass through the holes 45 therein. In additon to the holes 52, the support plates are provided, at each end, with a respective elongate slot 54, corresponding slots 55, 56 are provided in the top flanges 44 of the angle brackets 41 and 42. The shell 31 is mounted on the mount by means of suitable fasteners which pass through these slots 54, 55, 56 and into attachment devices provided within the material of the shell, these being indicated in dotted outline at 57 in FIGS. 5 and 7.

The mount is shown assembled in FIGS. 5, 6 and 7 and it will be seen that the depending webs 40 of the respective angle brackets 41 and 42 are clamped firmly against the resilient pads 39 which, in turn, are clamped firmly against the hollow face portions 38 of the centre plate means 36. This clamping is achieved by means of adjustable bolt and nut assemblies 58. When the pads are clamped most firmly, by tightening the bolt and nut assemblies 58, the rocking action of the chair is at its stiffest, whilst loosening these bolt and nut assemblies 58 releases the compression of the pads 39 somewhat and gives rise to a more vigorous rocking action. The attachment of the mount to the underside of the seat via the slots 54, 55, 56 enables adjustment of the bolt and nut devices 58 to be carried out without interference with the attachment of the mount to the seat.

The rocking action of the chair can best be described with reference to FIG. 7 of the drawings. As the seat rocks rearwardly with respect to the base, the pad 31 on the left-hand side of the figure is compressed whilst that on the right-hand side is relaxed. The buildup of compression in the left-hand side pad exerts a reaction force on the seat which causes it to rock forwardly, that is towards the right-hand side of FIG. 7. Slight fore and aft movement of the angle brackets 41 and 42 relative to the support plate 46 is allowed for by the slots 54, 55, 56 by which these parts are secured to the underside of the seat.

The weight of the seat and its occupant is transmitted to the two support plates 46 which, as seen in FIG. 5, are the only parts of the assembly which are in direct contact with the underside of the seat. The weight is then taken on the support pivots 48 and transmitted directly to the centre plate means 36 and hence to the spindle 34 of the base.

Very little loading takes place of either the angle brackets or the bolt and nut assemblies 58 because of the provision of the support pivots 48. It will be appreciated that, during rocking movement of the seat, some slight loading will occur on one of the two angle brackets at any given time. For example if the seat is rocked forwardly, some slight loading, due to the rocking movement, is transmitted to the angle bracket 41 and hence through the bolt and nut assembly 58 to the centre plates 36. However, the major part of the weight of the seat is transmitted directly through the support plates to the support pivots 48 and hence directly to the centre plate means. Under no circumstances is the resilient material of the pads 31 subjected to shearing forces which would reduce its life considerably.

The curvature of the seat 47 provided below the support plates 46 is such that the support plates remain in contact at all times with the upper surfaces of their respective support pivots 48.

Since the load is transmitted directly downwardly through the centre plate means 36 to the spindle 34, the lower end of the spindle 34 must be housed in what is effectively a thrust bearing and this is achieved by making the spindle as a hollow tube having a partly closed lower end within which a low friction pivot 59 is provided, this pivot being made of nylon or other low friction synthetic plastics material. The pivot 59 bears on a bottom plate 60 of a socket member 61 to which the legs 33 are secured. As mentioned above the spin dle 34 tapers inwardly towards its upper end and a suitable bearing bush 62 is interposed between the spindle and the socket 61 to assist in supporting the spindle. The lower end of the spindle is slightly deformed at 63 so as to be retained in position within the socket 61 and bearing sleeve 62.

We claim:

1. A mount for tiltably mounting the seat of a chair on a base, the mount comprising a rigid upright centre plate means, having a midportion supported by a portion of the base and having two free end portions disposed at opposed lat eral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat;

a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof;

resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween;

and a support plate means interposed between the top webs and the seat and supported by said centre plate means to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base.

2. A mount for tiltably mounting the seat of a chair on a base, the mount comprising a rigid upright centre plate means, having a mid portion supported by a portion of the base and having two free end portions disposed at opposed lateral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat;

a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof;

resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween;

a pair of support pivots mounted on respective free end portions of the centre plate means;

and a pair of support plates each interposed between the top web and the seat at a respective lateral side thereof and each resting on a respective one of said support pivots to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base, the support plates and support pivots having co-operating contact surfaces which remain in contact throughout rocking movement of the seat relative to the base. 3. A rocking chair comprising a base adapted to stand on a floor surface, a seat, and a mount whereby the seat is mounted on the base, said mount comprising a rigid upright centre plate means, having a midportion supported by a portion of the base and having two free end portions disposed at opposed lateral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat;

a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre'plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof;

resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween;

and a support plate means interposed between the top webs and the seat and supported by said centre plate means to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base.

4. A rocking chair comprising a base adapted to stand on a floor surface, a seat, and a mount whereby the seat is mounted on the base, said mount comprising a rigid upright centre plate means, having a midportion supported by a portion of the base and having two free end portions disposed at opposed lateral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat;

a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof;

resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween;

a pair of support pivots mounted on respective free end portions of the centre plate means;

and a pair of support plates each interposed between the top web and the seat at a respective lateral side thereof and each resting on a respective one of said support pivots to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base, the support plates and support pivots having co-operating contact surfaces which remain in contact throughout rocking movement of the seat relative to the base.

5. A rocking chair according to claim 3 wherein the base comprises a floor engaging part and a spindle mounted for rotation relative to the floor engaging part, said spindle constituting said portion of the base on which the centre plate means is supported. 

1. A mount for tiltably mounting the seat of a chair on a base, the mount comprising a rigid upright centre plate means, having a mid-portion supported by a portion of the base and having two free end portions disposed at opposed lateral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat; a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof; resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween; and a support plate means interposed between the top webs and the seat and supported by said centre plate means to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base.
 2. A mount for tiltably mounting the seat of a chair on a base, the mount comprising a rigid upright centre plate means, having a mid-portion supported by a portion of the base and having two free end portions disposed at opposed lateral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat; a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof; resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween; a pair of support pivots mounted on respective free end portions of the centre plate means; and a pair of support plates each interposed between the top web and the seat at a respective lateral side thereof and each resting on a respective one of said support pivots to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base, the support plates and support pivots having co-operating contact surfaces which remain in contact throughout rocking movement of the seat relative to the base.
 3. A rocking chair comprising a base adapted to stand on a floor surface, a seat, and a mount whereby the seat is mounted on the base, said mount comprising a rigid upright centre plate means, having a mid-portion supported by a portion of the base and having two free end portions disposed at opposed lateral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat; a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof; resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween; and a support plate means interposed between the top webs and the seat and supported by said centre plate means to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base.
 4. A rocking chair comprising a base adapted to stand on a floor surface, a seat, and a mount whereby the seat is mounted on the base, said mount comprising a rigid upright centre plate means, having a mid-portion supported by a portion of the base and having two free end portions disposed at opposed lateral sides of said portion of the base, the centre plate means being entirely free from attachment to the seat; a pair of angle brackets, each having a generally horizontal top web and a generally vertically depending upright web, said upright webs being arranged parallel to the centre plate means on opposed faces thereof, the respective top webs having their free edges directed away from the centre plate means and being secured to the underside of the seat adjacent the lateral sides thereof; resilient pads secured between each upright web and the adjacent face of the centre plate means to enable relative rocking movement therebetween; a pair of support pivots mounted on respective free end portions of the centre plate means; and a pair of support plates each interposed between the top web and the seat at a respective lateral side thereof and each resting on a respective one of said support pivots to transmit at least a major part of the weight of the seat to the centre plate means and hence to the base, the support plates and support pivots having co-operating contact surfaces which remain in contact throughout rocking movement of the seat relative to the base.
 5. A rocking chair according to claim 3 wherein the base comprises a floor engaging part and a spindle mounted for rotation relative to the floor engaging part, said spindle constituting said portion of the base on which the centre plate means is supported. 